The move came at the request of Riverside County, which wants to erect an electronic billboard near Cabazon where the Morongo Band of Mission Indians operate a 148,000 square foot casino, 310-room hotel, spa and outlet mall.

“Riverside wants to reduce congestion and clutter in the area by consolidating some billboards,” said the bill’s author, Sen. Bill Emmerson, a Riverside Republican.

“It’s easier to accomplish that by removing the scenic designation than changing the county general plan.”

However, the Assembly Transportation Committee said excising such a small section violated the “integrity of the scenic highway system.”

So the bill signed by Brown now prevents I-10 from Redlands east to roughly the Highway 111 exit to Palm Springs from receiving scenic highway status.

Although the route has been eligible for scenic status for 50 years, Riverside County has never sought official designation.

Given the development in the area over the past half-century, the land abutting the eight-or-more lane freeway wouldn’t win the designation anyway, as a 2011 review by Caltrans concludes. There’s too much “visual intrusion,” Caltrans told the Riverside County Board of Supervisors, which requested the appraisal.

Chief among the intrusion is the brightly lit 2,700-slot Morongo casino, its sprawling parking lot and 27-story hotel – the tallest structure in the Inland Empire.

Caltrans also identified as “visual intrusion” railroad tracks and an active gravel pit within the 1.12-mile area the county sought exempted.

Under California’s 50-year-old Scenic Highways program, the state decides what highways are eligible to receive the distinctive orange poppy signposts.

Among the advantages of the designation are preventing “encroachment of incompatible land uses such as junkyards, dumps, concrete plants and gravel pits,” according to the Caltrans website.

Various criteria are used in determining eligibility.

Highway 49, meandering through California’s Gold Rush county, easily qualifies since it links “specific scenic, historical and recreational points or areas of interest.”

Like Highway 1 hugging the rugged coast of Central and Northern California, Highway 49 also showcases miles of the Golden State’s unique natural features.

Once Caltrans says a route is eligible, the city or county where the highway is located must detail how their land use policies will keep the highway scenic, including control of outdoor advertising.

Caltrans can OK a scenic highway but can’t strip a roadway of the designation or eligibility. Hence, Emmerson’s bill.

“The county states the segment’s continued eligibility in the (scenic highways) program prevents critical economic development and the creation of a path towards recovery,” according to the Senate Floor Analysis of Emmerson’s bill.

Riverside has wanted to place an electronic billboard near the Morongo casino since 2007. Among the county’s stated reasons are consolidating some of the area’s other billboards into one location and making money by doing so.

The visibility of the new billboard – both its size and location – would make it desirable for advertisers, the county says.

Revenue from the billboard will be earmarked for easing congestion on the affected section of I-10 and creating other digital boards to provide public service announcements for motorists.